The present invention relates to a manifold with a built-in thermoelectric module. Further, the present invention relates to a cooling device having a thermoelectric module and also to the module itself.
Recently, flon gases have been reported as the cause of the worldwide problem of ozonosphere destruction. Therefore, it has been required to develop as soon as possible new cooling devices or apparatuses operating without any flon gas. Among such devices or apparatuses that have been proposed, one that comprises a thermoelectric module is attracting attention in this field of industries.
Those thermoelectric modules are also known as Peltier modules and have each a pair of heat transfer faces or plates such that one of them will be heated, with the other being cooled, as an electric current is fed through them.
An example of the cooling devices using the thermoelectric modules is disclosed in the gazette xe2x80x9cWO92/13243xe2x80x9d (of International Patent Application No. PCT/AU92/00008).
The prior art shown in this gazette xe2x80x9cWO92/13243xe2x80x9d proposes a manifold having a thermoelectric module built therein in such a manner that two opposing cavities formed in the manifold is partitioned with said module. One of those cavities is in contact with one of the heat transfer faces that is being heated, wherein a closed circuit comprising a heat exchanger and a pump extends through the one cavity. Likewise, the other cavity in contact with the other transfer face being cooled communicates with another closed circuit also comprising a further heat exchanger and a further pump. Thus, two circulation systems are provided for heat exchanging media that may typically be water. One such system involves the heated face of the thermoelectric module, with the other system involving the cooled face thereof. The heat exchanger included in the latter system will work to cool down any desired foreign object, article or the like.
The prior art, that is the preceding invention shown in the gazette xe2x80x9cWO92/13243xe2x80x9d, provides a practical cooling technology utilizing the thermoelectric module. However, since this invention merely teaches a basic structure of the cooling devices or apparatuses, some features or drawbacks of said structure have to be improved or resolved if and when it is applied to refrigerators or the like.
For example, those cooling devices of the thermoelectric module type are of a cooling efficiency lower than those of the known and conventional flon gas type.
In order to achieve a higher efficiency, the structure which the gazette xe2x80x9cWO92/13243xe2x80x9d has taught must be improved in respect of the structure of said module""s heat transfer faces and the heat exchanging media kept in contact therewith.
Another gazette xe2x80x9cWO95/31688xe2x80x9d (of International Patent Application No. PCT/AU95/00271) discloses a further previous invention comprising a means for raising efficiency of heat exchange between the thermoelectric module and the heat exchanging media. This invention teaches agitators that are disposed in cavities formed in a manifold so as to increase effective contact areas of said media with the module.
It is however to be noted that any practical means for driving the agitators within the cavities is not proposed in the gazette xe2x80x9cWO95/31688xe2x80x9d. Although the agitators installed in the cavities may be somewhat useful in resolving the problem discussed above, any suggestion on how to rotate the agitators is not given therein.
Those agitators in xe2x80x9cWO95/31688xe2x80x9d which will rotate anyhow to increase the effective contact areas of the module with the heat exchanging media is likely to produce bubbles in or bring bubbles into the cavities, undesirably resulting in less effective contact of said module with said media.
The thermoelectric module in xe2x80x9cWO95/31688xe2x80x9d is rendered round or circular in shape for the purpose of smooth rotation of the agitators within the manifold""s cavities.
An example of such module employed in xe2x80x9cWO95/31688xe2x80x9d is of a structure or shape as shown herein in FIGS. 20 and 21.
FIG. 20 is a front elevation of the round thermoelectric module used in xe2x80x9cWO95/31688xe2x80x9d, and FIG. 21 is a cross section of this module.
In FIGS. 20 and 21, the reference numeral 200 denotes a Peltier element, and the further numerals 202 and 203 respectively denote electrodes and aluminum plates. As seen in these figures, the prior art round module consists of the Peltier element 200 and the electrodes 202 arranged generally to form a circular configuration, wherein those element is sandwiched between discs together with the electrodes.
The known structure disclosed in xe2x80x9cWO95/31688xe2x80x9d may possibly render it possible to make a circular thermoelectric module. However, it is not easy to commercially manufacture modules of such a conventional structure. More specifically, it is difficult to position the Peltier element 200 and those electrodes 202 within a generally round contour that these members have to assume as a whole.
It also is difficult to stack several Peltier elements one on another in a laminating fashion according to the prior art structure, even if such a composition might produce much lower temperatures.
In addition, the prior art cooling apparatus of the described thermoelectric module type has required certain pumps to circulate the heat exchanging media.
It is known in the art to employ a certain transmission of magnet type in order to drive the pumps for circulating the heat exchanging media (see xe2x80x9cWO94/18516xe2x80x9d).
The present invention, that was made in view of the problems inherent in the described prior art, does hereby propose a quite novel manifold whose built-in thermoelectric module can be kept well in an excellent contact with heat exchanging media so as to afford an improved efficiency of heat exchange.
Further, the present invention provides a newly developed circular thermoelectric module that is not only easy to manufacture but also is suited for laminated composition.
The present invention made to diminish the drawbacks in the prior art provides a manifold comprising a built-in thermoelectric module that has at least two heat transfer faces such that one of the faces is heated and the other face is cooled when an electric current is applied to the module, a manifold body covering at least one of the heat transfer faces and defining a cavity between the one face and the body, a medium inlet through which a heat exchanging medium flows into the cavity, and a medium outlet through which the medium flows out of said cavity, wherein the heat transfer faces of the thermoelectric module stands upright and the medium outlet is disposed in an upper region of the cavity.
Thus, the manifold of the present invention has the inlet and outlet formed for the heat exchanging medium to flow into and out of the cavity, with the thermoelectric module being disposed vertically and with the outlet being located in an upper region of said cavity. By virtue of this feature, any bubbles that might be entrained into the cavity will rise along the upright heat transfer faces. Those bubbles or air will then be discharged quickly through the outlet at the top of the cavity. Such a smooth discharge of bubbles contributes to better contact of the medium with the module""s faces, thereby affording a higher efficiency of heat exchange.
Preferably, the medium outlet may be slanted somewhat.
Such an oblique outlet which the manifold comprises will assist the bubbles to smoothly move away from the manifold.
Also preferably, agitators are disposed rotatably in the cavity.
From another aspect, the present invention made to resolve the drawbacks in the prior art provides a manifold comprising a built-in thermoelectric module that has at least two heat transfer faces such that one of the faces is heated and the other face is cooled when an electric current is applied to the module, a manifold body covering at least one of the heat transfer faces and defining a cavity between the one face and the body, a (first) agitator disposed in the at least one cavity and having a (first) shaft, a pump accompanied by the manifold and having a (second) agitator and a (second) shaft, with the shafts extending in alignment with each other, rotors respectively connected to the agitators, and a single stator surrounding both the rotors so that the stator and the rotors form a motor capable of rotating the (first) agitator in the cavity together with the (second) agitator of the pump.
In the manifold of this structure and having the built-in thermoelectric module, the single stator and the two rotors constitute the motor such that said rotors drive the agitator in the cavity together with the agitator of the pump. Therefore, the manifold is rendered integral with the pump and accordingly the number of necessary parts is reduced.
The manifold just discussed above is so constructed that the cavity per se will serve as another pump.
In one of preferable modes of the invention, the manifold body covers the thermoelectric module such that one cavity is provided beside the heated face of said module and within the body, with the other cavity likewise provided beside the cooled face. The agitators are installed in the respective cavities, and a transmission is provided for them to transmit torque of the one agitator in the one cavity to the other agitator in the other cavity so as to rotate them within the respective cavities.
From still another aspect, the present invention provides a manifold comprising a built-in thermoelectric module that has at least two heat transfer faces such that one of the faces is heated and the other face is cooled when an electric current is applied to the module, a manifold body covering the module so that one cavity is formed beside the heated face of said module and within the body, with the other cavity likewise formed beside the cooled face, agitators installed in the respective cavities, a driving means for rotating one of the agitators, and a transmission for transmitting torque of the one agitator to the other agitator so that as the one agitator is driven within the one cavity, the other agitator receives torque from the one agitator so as to rotate within the other cavity.
In the manifold of this structure, the heat exchanging media flow each in a circle within each cavity to thereby improve contact coefficient of the media contacting the module""s heat transfer faces, thus raising efficiency of heat exchange.
The single driving means can drive both the agitators located on respective sides of the heated and cooled faces of the module built in the manifold, whereby the number of constituent parts is reduced and the overall outer size of the manifold is decreased.
The agitators rotating within the respective cavities also contributes to efficient contact of the media with the module""s faces and thus affords a higher efficiency of heat exchange.
Desirably, transmission of force between the agitators may rely on magnetic mechanism.
In such a manifold having the built-in module, force or torque will be transmitted magnetically between the agitators. This non-contact type transmission is advantageous in that the cavities are insulated from each other and consequently one of the media being heated is protected from mixing with the other medium being cooled.
It also is desirable that outer dimension of the cavities is greater than that of the module""s heat transfer faces so that magnetic pieces constituting the magnetic transmission mechanism are fixed on agitators"" regions confronting the portion along and outside the periphery of the module.
The magnetic pieces or members employed in this structure are located along and outside the periphery of the thermoelectric module. In other words, magnetic pieces are apart from the module so as to protect the latter from magnetic influence.
In an alternative mode, a common shaft penetrates both the cavities so that torque of one agitator is transmitted by and through this shaft to the other agitator.
The manifold of this structure is advantageous in that power is directly transmitted from one agitator to the other, giving a higher efficiency of transmission.
The driving means mentioned above may generally be an electric motor, and a rotor of this motor will operatively be connected to one of the agitators. Preferably, the magnetic center line of the motor""s rotor is not in alignment with the magnetic center line of the stator mentioned above, and this line is offset rearwardly of the agitators.
It is preferable that the thermoelectric module repeatedly discussed above is of a circular contour.
Such a round configuration will diminish futile peripheral portions of the module built in the manifold.
Further, the module may consist of an element molded as a plate and a pair of heat conductive discs sandwiching same.
This plate-shaped module can substantially serve as a round thermoelectric module.
In another alternative mode, a plurality of Peltier elements are arranged and fixed in position to form a rectangular envelope to provide a rectangular thermoelectric element, and the latter is sandwiched by and between two or more discs.
Such an arrangement of the Peltier elements to form a rectangular group disposed between the two or more discs provides a rectangular or square composite module.
This module will generally have a round appearance.
The module of this substantially round type is easy to manufacture and suited to laminate Peltier elements with each other.
The rectangular thermoelectric element referred to above may preferably be prepared by sandwiching same with and between ceramics layers or aluminum oxide layers.
Further, those rectangular elements may be stacked one on another so as to produce much lower temperatures.
Additionally, those rectangular elements can also be arranged side by side and sandwiched between discs to provide a round composite module of a larger surface area. It is desirable that the discs noted above are of a rough outer surface adapted to enhance efficiency of heat exchange.
All the alternative thermoelectric modules summarized above and applicable to any mode of the present invention have not been known in the art.
The manifold body or casing may cover only one heat transfer face of the module, with the other face being secured to any appropriate heat conductive plate.
The manifold of this structure may be used to directly cool any ambient article or air by means of such a conductive plate.
From a further aspect of the invention, provided herein is a manifold comprising rectangular thermoelectric element in which a plurality of Peltier elements are arranged and which is sandwiched between discs so as to provide a generally round module, the round module having two heat transfer faces such that one of the faces is heated and the other face is cooled when an electric current is applied to the module, a manifold body covering the module so that one cavity is formed beside the heated face of said module and within the body, with another cavity being likewise formed beside the cooled face, the manifold body or casing having a medium inlet through which the medium flows into each cavity as well as a medium outlet through which the medium flows out of each cavity, wherein the heat transfer faces of the thermoelectric module stands upright and the medium outlet is disposed in an upper region of the cavity, agitators installed in each cavity, a transmission for magnetically transmitting torque of the one agitator to the other agitator, a pump secured to the manifold body and having further agitator with a shaft in alignment with a further shaft of the agitator, separate rotors connected to the agitator in the cavity and to the agitator of the pump, a stator surrounding both the rotors so that the stator and the rotors form a motor and when the agitator in one cavity as well as the agitator of the pump are driven the other agitator in the other cavity magnetically receives torque from the one agitator thus rotating within the one cavity.
Each of the described manifolds described hereinbefore and provided with the built-in thermoelectric modules is useful to construct a cooling apparatus. A piping will be connected to and between the manifold and an external heat exchanger so as to form a loop for the cooling apparatus.
In detail, the cooling apparatus provided herein does comprise manifold having a built-in thermoelectric module, an external heat exchanger and a loop-shaped piping connected to and extending between the manifold and the heat exchanger, wherein the manifold comprises at least two heat transfer faces such that one of the faces is heated and the other face is cooled when an electric current is applied to the module, a manifold body covering the module so that one cavity is formed beside the heated face of said module and within the body, with another cavity likewise formed beside the cooled face, agitators installed in the respective cavities, a driving means for rotating one of the agitators, and a transmission for transmitting torque of the one agitator to the other agitator so that as the one agitator is driven within the one cavity, the other agitator receives torque from the one agitator and rotates within the other cavity, and at least one of the agitators force the heat exchanging medium in the manifold to flow into and circulate through the piping.
It is noted here that the manifold comprising the built-in module has the agitators that are disposed in the cavities and urge the heat exchanging medium to circulate within the system, thus dispensing with any pump.
The manifold just referred to above may be replaced with another type of manifold also comprising a built-in thermoelectric module that has at least two heat transfer faces such that one of the faces is heated and the other face is cooled when an electric current is applied to the module, a manifold body covering at least one of the heat transfer faces and defining a cavity between the one face and the body, a (first) agitator disposed in the at least one cavity and having a (first) shaft, a pump accompanied by the manifold and having a (second) agitator and a (second) shaft, with the shafts extending in alignment with each other, rotors respectively connected to the agitators, and a single stator surrounding both the rotors so that the stator and the rotors form a motor capable of rotating the (first) agitator in the cavity together with the (second) agitator of the pump.
Alternatively, the manifold just referred to above with respect to the cooling apparatus may be replaced with another type of manifold also comprising a built-in thermoelectric module that has at least two heat transfer faces such that one of the faces is heated and the other face is cooled when an electric current is applied to the module, a manifold body covering at least one of the heat transfer faces and defining a cavity between the one face and the body, a medium inlet through which a heat exchanging medium flows into the cavity, a medium outlet through which the medium flows out of said cavity, and an agitator disposed and rotating in the cavity, wherein the heat transfer faces of the thermoelectric module stands upright and the medium outlet is disposed in an upper region of the cavity.